Use CSS to style your React Native apps.
Behind the scenes the .css files are transformed to react native style objects (look at the examples).
This transformer can be used together with React Native CSS modules.
Your App.css file might look like this:
.myClass {
color: blue;
}
.myOtherClass {
color: red;
}
.my-dashed-class {
color: green;
}When you import your stylesheet:
import styles from "./App.css";Your imported styles will look like this:
var styles = {
myClass: {
color: "blue"
},
myOtherClass: {
color: "red"
},
"my-dashed-class": {
color: "green"
}
};You can then use that style object with an element:
Plain React Native:
<MyElement style={styles.myClass} />
<MyElement style={styles["my-dashed-class"]} />React Native CSS modules using className property:
<MyElement className={styles.myClass} />
<MyElement className={styles["my-dashed-class"]} />React Native CSS modules using styleName property:
<MyElement styleName="myClass my-dashed-class" />npm install --save-dev react-native-css-transformeror
yarn add --dev react-native-css-transformerMerge the contents from your project's metro.config.js file with this config (create the file if it does not exist already).
metro.config.js:
const { getDefaultConfig } = require("expo/metro-config");
module.exports = (() => {
const config = getDefaultConfig(__dirname);
const { transformer, resolver } = config;
config.transformer = {
...transformer,
babelTransformerPath: require.resolve("react-native-css-transformer")
};
config.resolver = {
...resolver,
sourceExts: [...sourceExts, "css"]
};
return config;
})();Merge the contents from your project's metro.config.js file with this config (create the file if it does not exist already).
metro.config.js:
const { getDefaultConfig, mergeConfig } = require("@react-native/metro-config");
const defaultConfig = getDefaultConfig(__dirname);
const { assetExts, sourceExts } = defaultConfig.resolver;
/**
* Metro configuration
* https://reactnative.dev/docs/metro
*
* @type {import('metro-config').MetroConfig}
*/
const config = {
transformer: {
babelTransformerPath: require.resolve("react-native-css-transformer")
},
resolver: {
sourceExts: [...sourceExts, "css"]
}
};
module.exports = mergeConfig(defaultConfig, config);:root {
--text-color: blue;
}
.blue {
color: var(--text-color);
}CSS variables are not supported by default, but you can add support for them by using PostCSS and postcss-css-variables plugin.
Start by installing dependencies:
yarn add postcss postcss-css-variables react-native-postcss-transformer --devRemove CSS transformer from the project:
yarn remove react-native-css-transformerAdd postcss-css-variables to your PostCSS configuration with one of the supported config formats, e.g. package.json, .postcssrc, postcss.config.js, etc.
After that replace the transformer name in your Metro config file (metro.config.js):
-require.resolve("react-native-css-transformer")
+require.resolve("react-native-postcss-transformer")This library has the following Node.js modules as dependencies: